開發(fā)過程中總會(huì)遇到一些需求需要對(duì)圖片格式進(jìn)行轉(zhuǎn)換。比如 gif轉(zhuǎn)png,jpg轉(zhuǎn)png
/**
* 圖片格式轉(zhuǎn)換
* @param string $image_path 文件路徑或url
* @param string $to_ext 待轉(zhuǎn)格式,支持png,gif,jpeg,wbmp,webp,xbm
* @param null|string $save_path 存儲(chǔ)路徑,null則返回二進(jìn)制內(nèi)容,string則返回true|false
* @return boolean|string $save_path是null則返回二進(jìn)制內(nèi)容,是string則返回true|false
* @throws Exception
* @author klinson klinson@163.com>
*/
function transform_image($image_path, $to_ext = 'png', $save_path = null)
{
if (! in_array($to_ext, ['png', 'gif', 'jpeg', 'wbmp', 'webp', 'xbm'])) {
throw new \Exception('unsupport transform image to ' . $to_ext);
}
switch (exif_imagetype($image_path)) {
case IMAGETYPE_GIF :
$img = imagecreatefromgif($image_path);
break;
case IMAGETYPE_JPEG :
case IMAGETYPE_JPEG2000:
$img = imagecreatefromjpeg($image_path);
break;
case IMAGETYPE_PNG:
$img = imagecreatefrompng($image_path);
break;
case IMAGETYPE_BMP:
case IMAGETYPE_WBMP:
$img = imagecreatefromwbmp($image_path);
break;
case IMAGETYPE_XBM:
$img = imagecreatefromxbm($image_path);
break;
case IMAGETYPE_WEBP: //(從 PHP 7.1.0 開始支持)
$img = imagecreatefromwebp($image_path);
break;
default :
throw new \Exception('Invalid image type');
}
$function = 'image'.$to_ext;
if ($save_path) {
return $function($img, $save_path);
} else {
$tmp = __DIR__.'/'.uniqid().'.'.$to_ext;
if ($function($img, $tmp)) {
$content = file_get_contents($tmp);
unlink($tmp);
return $content;
} else {
unlink($tmp);
throw new \Exception('the file '.$tmp.' can not write');
}
}
}
// 轉(zhuǎn)換后保存在test.png
transform_image($url, 'png', './test.png');
transform_image($filepath, 'png', './test.png');
// 轉(zhuǎn)換后二進(jìn)制結(jié)果直接返回
transform_image($url, 'png');
transform_image($filepath, 'png');